s S W L F SynergyRTM B R A C K E T S Y S T E M

Transcription

1 s S W L F SynergyR B R A C K E T S Y S T E M

2 SWLF bracket SYNERGY R By Robert T. Rudman D.D.S., M.S. Denver, CO REVIEW OF SELF-LIGATION Although the idea of self-ligating brackets dates back to the 1930 s with the Russel Lock edgewise attachment, it is only within the last decade that self-ligating brackets are attracting more interest. There have been many journal articles defining what an ideal self-ligation system might look like. Harradine described these properties as: BEFORE Secure and robust AFTER After images represent first scheduled retie appointment at only 10 weeks All of us as orthodontists are experiencing vast changes in our profession. The speed at which technological and market demands sweep the globe touch every aspect of our practice. These changes include a move towards low force/low friction bracket systems that hold the promise of treating patients in reduced time and less visits. Demands from our patients for an efficient and effective orthodontic experience with outstanding results leaves little room for missteps along the way. All these changes are occurring amongst the backdrop of a generalization of orthodontics, a competitive orthodontic landscape, and a changing economy. The 2003 JCO survey indicated that median case starts have declined for the first time since the survey began in With the vast array of clinical systems we have at our disposal and the effect that these choices will have on our day to day practice experience, clinical results, profitability, and ultimately the patient s experience, the impact of the decisions we make are far reaching. In my practice, any decisions to implement a new system, whether brackets, software or equipment, must meet three distinct criteria. The system must be synergistic, efficient, and effective. Synergy is defined as the interaction of two or more agents or forces so that their combined effect is greater than the sum of their individual effects. Efficient is defined as performing or functioning in the best possible manner with the least waste of time, effort, skill, or resources. Effective is defined as the ability to accomplish a purpose; producing the intended or expected result. With this in mind I would like to discuss the implementation of two new systems from RMO that I have incorporated into my practice: the SWLF Synergy R bracket system, and Indirect Bonding. Ensure full bracket engagement of the arch wire Exhibit low friction between the bracket and arch wire Be quick and easy to use Permit high friction when desired Permit easy attachment of elastic chain Be comfortable for the patient SELF-LIGATING BRACKETS Faster Arch Wire Changes: Maijer and Smith found a four-fold reduction in ligation time compared to wire ligation of conventional brackets3, but when compared to elastomeric ligatures, arch wire change time savings are less dramatic at approximately 1 minute faster per arch wire4. Moving Parts: Moving parts in a bracket system introduce unique challenges. The literature has reported breakage, inadvertent opening, difficulty in opening, difficulty in visualizing the spring clips due to gingival overgrowth and/or excess composite around the bracket pad,5,6 brackets that close inadvertently before the arch wire is in position causing difficulty seating the arch wire, retention of flexible clips can be overcome by larger rectangular wires, difficulty in removing thicker archwires5, contraindicated on patients with calculus forming tendencies making clips difficult to open, removal of calculus on clips risking debond6. Active Clip: An active clip effectively reduces slot depth. The claims that active clips act passively only holds true if the teeth are aligned. Harradine accurately described if the tooth (or part of the tooth is rotated) is sufficiently lingually placed, a higher total force will be applied in comparison to the passive clip. Another misunderstanding explained by Harradine is the fact that an active clip places a diagonal force on the wire which does not contribute to third order (torque) interaction. The depth of one side (occlusal or gingival) of an active clip slot is reduced which means the rectangular wire is not fully engaged. This increases the slop between the rectangular wire and the slot. Harradine stated that these factors probably explain the reported additional difficulties in finishing cases with some examples of this bracket type. In a thick working arch wire an active clip would create more friction.5 Passive Clip: It has been reported that passive clips may have the advantage of reduced friction in the initial stages of treatment but at the expense of three dimensional control. It has been suggested that the passivity of these brackets acts like a buccal tube and unless a full size S.S. arch wire is used, which might be too stiff to insert, undesirable torque may result. Kusy and Thorstenson have stated that although a low value of resistance to sliding may be beneficial during the early stages of treatment, a higher value might be optimal for later stages. SWLF SYNERGY R BRACKET SYSTEM RMO s first self-ligating bracket ( Snap Channel ) was developed in the 1930 s. Over the years RMO became aware of the advantages and disadvantages of self-ligation and incorporated their latest technological developments to create SWLF Synergy R, a bracket system that delivers the benefits of self-ligating while eliminating the majority of limitations associated with self-ligating. CHARACTERISTICS OF SWLF SYNERGY R IN CLINICAL USE SWLF Synergy R Bracket Faster arch wire changes (38% less time in my office) Figure 1a No moving parts to deform or break Conventional Twin Bracket No doors or clips No need for crimpable stops on the arch wire or dimpled wires No need for posted arch wires due to Energy Chain not binding wire (Figures 1a & 1b) Offset bicuspids available Figure 1b Note the space between the arch wire and the Energy Chain FSC FRICTION SELECTION CONTROL No need to use hybrid or rounded arch wires to avoid sensitivity caused by clip engagement/disengagement forces on incisors Figure FSC Benefit of a passive ligation in the early and middle stages of treatment for rapid alignment, leveling, and sliding mechanics REDUCED FRICTION The option of easily converting the bracket to full 3D control in the detailing phase After conversion, elastomerics can still be employed in a reduced friction configuration (Fig FSC ) A true rectangular slot size available in both.018 and.022 Flexibility of bidimensional technique if desired MODERATE ROTATION Extended treatment appointment intervals Respect for the patient s desire for colors as part of the system keeps the fun in treatment MAXIMUM ROTATION No double ligation of closing doors and then ligating colors cutting into the time efficiency of arch wire changes Patients want colors on the incisors 60% less ligation - 8 (incisor) brackets vs. 20 RMO ConverTechnology assures easy conversion only when desired CONVENTIONAL CONTROL Expense: Self-ligating brackets are reported to cost anywhere from two to four times the cost of a quality conventional bracket. For the practice that starts 250 cases per year, for every two dollar increase per bracket expenditure, the clinician will realize over a 2.6 million dollar impact to the bottom line over a 30 year career* (assuming savings are invested and a 10% return). Convertible cap insures integrity of the slot dimensions when debonding and repositioning by adding a fourth wall to the slot No special tools needed for ligation Familiar mechanics MAXIMUM CONTROL

3 It is easier to place detail bends on incisors with SWLF Synergy R because ligatures allow the arch wire to be pulled to the base of the slot on incisors for optimal activation and alignment of contacts leveling and aligning phase of treatment. Suarez refers to this effect as the Dynamic Friction Angle.11 (Fig. 2a, 2b, 2c) The unique arch wire slot design also allows for easier insertion of arch wires due to the inherent funneling effect the entry and exit path of the slot exhibits on the wire (Fig 3-blue arrows). 2A Familiar technique - no implementation headaches Mesial distal width of the convertible cover is similar in dimension to a twin bracket for excellent rotational control (Fig 3 - red). For even more control, the orthodontist can utilize the full dimension of the synergy outer wings when ligated traditionally. Bracket costs in line with quality traditional twin brackets Detailing of the occlusion with familiar/traditional 3D control Positioning of the bracket is simplified with engineered visual cues. The scribe mark is built into the face of the center wing and its junction with the convertible cap, forming a marksman s like cross-hair for proper crown and root angulation (Fig 3 - yellow). SWLF prescription option of 0 or -6 degree lower anteriors 2B THE SWLF SYNERGY R BRACKET The SWLF Synergy R bracket builds on the long established success of RMO s Synergy series brackets. The slot design of SWLF Synergy R incorporates rounded arch slot walls both occlusal/gingivally and buccal/ lingually, allowing for an increased effective interbracket distance as well as the reduction of binding forces that arch wire slots ending in 90 degree angles may introduce in the initial The three sets of wings have been reconfigured for ease of the various ligation options that SWLF Synergy R offers the orthodontist. 2C The Dynamic Friction Angle (DFA) between slot and archwire is very important in sliding in the initial phases of treatment. RMO ConverTechnology: RMO s patented ConverTechnology is at the heart of the SWLF Synergy R bracket system. This tried and true proprietary technology utilizes a cutting edge Metal Injection Molding (MIM) process that molds the cap directly into the bracket, thereby eliminating the manual soldering of traditional convertible tubes that is riddled with problems introduced by human variation. This means that manufacturing tolerances can be tightly controlled, ending premature conversion as well as eliminating caps that are too hard to convert and that can compromise the bonded bracket. This gives the orthodontist the option of going from a friction free mode to traditional mechanics in seconds. ARCH WIRE INSERTION There are no special tools or training to place arch wires. In fact, you and your staff have been utilizing this technique as long as you ve been threading arch wires through molar tubes. Since the SWLF Synergy R system is a low friction system, depending upon the irregularity index of the teeth the initial arch wire is a.013 or a.015 Orthonol. These initial wires have been specifically designed by RMO for the SWLF Synergy R system. The initial arch wire form is 15% larger than the natural form that will be utilized once rectangular wires are introduced. The rounded walls of the arch wire slot provide an easy entry and exit path for the arch wire threading. template to determine initial arch wire length Fig 4) and placed in the right and left canine brackets (Fig 5). The wire is then threaded through to the terminal molar on one side and then the other. Midlines are lined up with the arch wire and the 2-2 brackets are ligated in usual fashion with the color of our patient s choice. In our office this method has reduced arch wire change time an average of 38% over standard elastomeric ligation. The operator has the flexibility to utilize all the ligation options SWLF Synergy R affords. We tend to ligate the incisors around all the wings initially for full rotational control. Ligation of the incisors only does away with time consuming stops and the guess work of where to place them. There is no need for the additional inventory of dimpled wires since arch wire creep is controlled and the variety of ligation modes can be employed when indicated (Fig FSC ). Generally at the second or third appointment (12 or 24 weeks in our office) we insert a Thermaloy arch wire. TIP: In rectangular arch wire insertion, utilizing the initial round arch wire as a template, use a distal end cutter to cut the rectangular wire at a distal lingual bias forming a point and enhancing the ease of arch wire threading (Fig 6). The arch wire is cut to length (TIP: We use the indirect bonding tray of each arch as a ENERGY CHAIN Because of SWLF Synergy R s unique design, the Energy Chain does not touch the arch wire and soldered posted wires are not needed to avoid binding of the Energy Chain as in all other systems (Fig 1a, 1b). With the drastic reduction in friction by ligating around the center wings only, closed Energy Chain is generally contraindicated and open chain keeps the forces in a physiological realm. A good example of this is indicated in Fig 8a and Fig 8b where open chain was stretched and released, the rebound shows friction free effect (Fig 8a) for SWLF Synergy R vs. frictional elastomeric binding (Fig 8b) for competitor s brackets. The well documented long acting forces of RMO Energy Chain are an integral part of lengthened appointment intervals, and the product allows patients a variety of color choices (or clear for ceramics) also. Although indirect bonding has greatly reduced the need, there is little argument for the efficiency of repositioning brackets vs. arch wire bends for error in bracket position. After a progress panorex has been taken, the integrated convertible cap adds a fourth wall to the bracket slot, thereby minimizing arch slot distortion when brackets are debonded for repositioning. The elegance of the system gives clinicians the option of repositioning or converting all the brackets to standard straight wire for detailing bends. 4 5 APPOINENT INTERVALS After experience with the system I have found 12 week intervals in the initial leveling and aligning phases to be ideal. I have moved initial intervals from 6 to 8 to 10 to now 12 weeks. I find that the light forces inherent in the system do not over power the occlusion and oral musculature, allowing these extended intervals without loss of control over the case. I have realized a huge benefit by allowing the adaptation of the oral environment to the physiological tooth moving forces over these extended intervals vs. one s natural predilection to jumping in and forcing things to happen. Depending upon the irregularity index of the teeth, I typically begin a case with RMO s specially designed SWLF Synergy R.013 or.015 Orthonol (15% larger than the natural form). This wire generally serves for the first weeks, at which point I shift to a Thermaloy (natural form) for the following weeks. Depending upon the needs of the case, up to a Bendaloy wire can be placed without converting the system. When jumping up to steel wire and above, it is advisable to convert only the canines using the RMO cap converting instrument (Fig 7a, 7b, & 7c). 6 7A 7B 7C 3 REPOSITIONING OF BRACKETS 8A 8B

4 Note: All cases were indirect bonded with RMO s bondindirect bonding system Note: All cases were indirect bonded with RMO s Case 1 Patient treatment planned for asymmetrical 4 bicuspid extraction due to Class III left Class II right occlusal relationship. Upper and lower arch were indirect bonded (note initial position of maxillary lateral). Lower cuspid was left unligated to allow lateral to move freely and to act as a reference tooth..014 Thermaloy maxillary arch/.013 Thermaloy mandibular arch inserted at bonding appointment. Patient was instructed to wear very light class II elastics while sleeping. At 10 weeks after initial bonding, photos were taken and.016 Thermaloys were placed. Of particular interest is the lack of incisor flaring due to the low force wires not overpowering the oral musculature. Rapid space closure occurred with no Energy Chain due to the ability of teeth to drift under the lack of binding forces normally found in traditional ligation. bond indirect bonding system Case 2 Patient indirect bonded with posterior turbo s and.016 Orthonol wires placed. Follow up photos taken at 11 weeks after initial bonding when Orthonol wires were placed. Of particular note is the uprighting of the lower arch allowing rapid alignment and nice arch form on a very light wire. Upper left central was not ligated around all wings because Day of Bonding of it s seemingly good initial position. This has lead to ligating all wings of the incisors on the Day of Bonding majority of our cases. 1st scheduled retie appointment at only 11 weeks 1st scheduled retie appointment at only 11 weeks Case 3 Transfer patient treatment planned for 4 bicuspid extraction to address bi-maxillary protrusion, dolichocephalic skeletal pattern and the patient s chief complaint of fullness of profile. Patient indirect bonded,.016 Thermaloy wires placed, scheduled to be back in 6 weeks to remove arch wire for 4-bicuspid extractions by referring dentist. Of particular note is that this patient did not come back to our office for 24 weeks, so the progress photos are of this first appointment. Upon examination of the photographs (a new ceph in 24 weeks would not be in the patient s best interest), there appears to be no increase in flaring compared to the initial photos. No mechanics for vertical control of the open bite tendency were employed. Patience with not overpowering the teeth and time (although inadvertent in this case) allowed significant leveling, decrowding, and alignment while the teeth and musculature adapted to keep a difficult case in good control. Patient was sent for the extractions. After treatment - total of 16 months 1st appointment at 24 weeks - patient disappeared and did not return until these photos 1st appointment at 24 weeks - patient disappeared and did not return until these photos 1st appointment at 24 weeks - patient disappeared and did not return until these photos

5 Note: All cases were indirect bonded with RMO s bond indirect bonding system teeth can be pulled towards the buccal. You can re-tighten the ligature or thread it through depending on the displacement (Fig 11). Case 4 Patient presented with high cuspid and right buccal segments in cross bite..013 SWLF Synergy R wire in.018 slot at 9 week follow up. 4. Another thoughtful design attribute is the malleable centered hook. Run the wire under the hook in the middle of the bracket (skipping the slot). Because the hook is in the center it allows easy access and pulls the center of the tooth buccally, aligning the teeth. The bracket hook is very malleable, so you can orient it in towards the gingival to better hold the arch wire (Fig 12). Adding Energy Chain will provide de-rotational movement if desired (Fig 13). By combining these two techniques the clinician can align the bracket buccal/lingually and also rotate the misaligned tooth in a reduced friction environment. You can then typically thread the arch wire through the arch slot during the next appointment. (I will usually schedule patients back in 2-4 weeks depending on the severity of rotation and then put them on a regular week schedule after the wire is threaded through the slot.) wax on the RMO converting pliers to catch the integrated cap, making sure the instrument is seated in the mesial entrance of the arch wire slot underneath the cover and the blunt end of the instrument is resting on the distal. Squeeze lightly and you will feel three distinct clicks, this is the patented RMO ConverTechnology cap releasing the cover at the proper force (Fig 14a & 14b). 6. The Interaction of the SWLF Synergy R bracket system with RMO s RMbond indirect bonding system synergizes the efficiency and effectiveness of treatment. 5. Converting: In our office it is extremely rare to convert anything but the canine brackets once in heavy wires. Place a piece of orthodontic 1st scheduled retie appointment at only 9 weeks CLINICAL TIPS In this article, I have included the very first cases using the SWLF Synergy R prototype brackets. You will notice an array of arch wire sizes and appointment intervals, degrees of difficulty, and treatment plans prior to familiarity with how the system performs. The commonality is the speed of alignment, leveling, and uprighting in very light wires that the SWLF Synergy R accomplished. Since finishing employs the familiar mechanics of traditional straight wire brackets, leveling, aligning and space closure will be discussed. Clinical situations vary immensely between patients, and although SWLF Synergy R is an easy system to implement there may be situations where bracket engagement is a challenge (Fig 9). The uniqueness of the SWLF Synergy R design gives the clinician versatility to overcome these clinical obstacles Make sure that you anneal the last 5 mm of the.013 wire before inserting, as this allows you to control the bias of the wire. Use a weingart or a scaler between the brackets when interbracket distance is an issue in order to guide/bend the dead soft wire to the next entrance of the following bracket. This is a built in design attribute of why the ConverTechnology convertible cap does not fully cover the width of the bracket (so you can access the wire). Most of the time on a difficult rotation, once you get a part of the annealed wire directed into the next bracket entrance you can push the wire through. Many times it is easier to push from a vantage point away from the mesial of the bracket in question, in order to thread the wire through. Sometimes you have to push vs. pull or pull vs. push, because the wire almost wants to find the path of least resistance. Otherwise, if you grab the wire just mesial of where you are threading it through it can be difficult and put an awkward vector of force on it. 10A I have had brackets that are touching due to rotations and this annealing works well as you can orient the wire by the permanent deformation ability of the annealed wire. (Obviously you will cut off the annealed part as the annealed aspect will be totally distal of the last molar tube so you have active wire working). 2. Just like a conventional bracket, if things are severely rotated you will only be able to partially engage the bracket. In this instance, take a steel quick tie or elastomeric and piggy back the wire across the slot cover and engage the wings. Because of SWLF Synergy R s 6 wing advantage, I will usually try to only engage 4 of the 6 wings (the middle and the wings closest to the rotation) (Fig 10a, 10b, & 10c). 10B A 10C 3. You can also take a steel ligature and thread it though the arch wire slot (under the convertible cover) and lasso the wire to the bracket cover and tighten it down (think of this as a vertical auxiliary slot except it is horizontal). You can also do this for very high cuspids where you run a regular steel lig in the slot and lasso the wire and bring it up to the cuspid (wire underneath occlusal tie wings). Very lingually displaced REFERENCES CASES 14B 1. Stollzenberg J. The Russel attachment and it s improved advantages. Int J orthodon Dent 1935; 21: Harradine NWT.Self-ligating brackets and treatment efficiency. Clin Orthod Res 2001;4: conventional an SL bracket design using standard archwires and dental typodonts. Angle Orthod 2004;75: Harradine N. Self Ligating Brackets :where are we now? Journal of Orthodontics 2003; 30: Parkin N. Clinical Pearl: Clincal Tips with System-R. Journal of Orthodontics : Rinchuse DJ, Rinchuse DJ, Kapur-Wadhwa R Orthodontic Appliance Design. Am J Orthod Dentofacial Orthop 2007; 131 : Maijer R, Smith DC. Time savings with self-ligating brackets. JClin Ortho : Cacciafesta V,Sfondrini MF,Ricciardi A, Scribante A, Klersy C, Auricchio F, Evaluation of the frictional Resistance of stainless steel and esthetic SL brackets in various bracket archwire combinations. Am J Orthod Dentofacial Orthop 2003:124: ) 10. Thorstenson GA, Kusy RP. Comparison of resistance to sliding between different SL brackets with second order angulation in dry and saliva states.. AM J Orthod Dentofacial Orthop 2002;122: Shivapuja PK,Berger J, A comparative study of conventional ligation and self- ligation bracket systems. Am J Orthod Dentofac Orthop 1994; 106: Henao SP, Kusy RP. Evaluation of the frictional resistanceof 11. Suarez D. Straight Wire Low Friction: Synergy System II. RMO conventionnews 2004;

6 S W L F SynergyR S Y N E R G Y R W I R I N G S E Q U E N C E Insert archwires with ease. SWLF Synergy R provides minimal friction and rapid wire changeout, with cuspid and bicuspid brackets that can be converted into traditional Synergy -style brackets at any time..018 ARCH SLOT.022 ARCH SLOT ALIGNMENT High Irregularity Medium Irregularity Low Irregularity WIRE TYPE MAXILLARY MANDIBULAR MAXILLARY MANDIBULAR Thermaloy Plus Thermaloy Plus Thermaloy Plus Optional SWLF Synergy R Orthonol Expanded Arch Form (Universal).013 Round (Part # A07700) (Part # A07704) (Part # A07705).013 (Part # E07000).013 Round (Part # A07720) (Part # A07724) (Part # A07725).015 Round (Part # A07702) (Part # A07705) (Part # A07705).015 (Part # E07001).015 Round (Part # A07722) (Part # A07725) (Part # A07725) LEVELING TRU-CHROME Stainless Steel (Part # A07205) (Part # A07207) (Part # A07225) (Part # A07227) (Part # A07207 (Part # A07208) (Part # A07227) (Part # A07228) FINISHING Bendaloy (Part # A07125) (Part # A07126) (Part # A07134) (Part # A07135) (Part # A07126).019 x.025 (Part # A07128) (Part # A07135).019 x.025 (Part # A07137) TIPS: If indirect bonding, use the bonding tray of each arch as a template to determine initial archwire length (leave an additional 5mm per side if annealing - see below) With a distal end cutter, trim archwires at a distal-lingual bias to form a point that enhances the ease of archwire threading (leave an additional 5mm per side if annealing - see below) Make sure to anneal the last 5mm of wire before inserting, as this will ease the threading process when interbracket distance is an issue Use a weingart or scaler between brackets to guide/bend the archwire tip to the next entrance of the following bracket It is often easier to push from a vantage point away from the mesial of the bracket in question, in order to thread the wire through Trim off annealed archwire tips to insure you have fully active wire working throughout the distal-most appliances MAXIMUM CONTROL REDUCED FRICTION FSC F R I C T I O N S E L E C T I O N C O N T R O L MODERATE ROTATION If severe malocclusion prevents threading of archwire through a particular bracket, try to piggy-back the wire across the convertible cap and use the tie wings or slot to engage with an elastomeric or steel ligature tie until alignment provides proper threading Bracket hooks are very malleable, and can be bent towards the gingival to improve patient comfort or to hold an archwire behind the hook when threading through the bracket slot is not possible When converting caps, place a piece of orthodontic wax on the RMO convertible cap plier tip to catch the integrated cap CONVENTIONAL CONTROL MAXIMUM ROTATION Colored Ligature Option Satisfy color requests even during unconverted bracket stages by ligating the center wings without compromising performance. The World s Oldest Synergistic, Bioprogressive, Breathing Enhancement Orthodontic Company P00742 Rev. A